Each network has its own servers, connecting with any of those servers will take you to the same "place". You and your friends dont have to be on the same server, just on the same network.
DALnet's random server (irc.dal.net) is set to not resolve in a way that you can connect with it. You can find a list of current DALnet servers on their website,
www.dal.net as well as on
http://edk.dyndns.org/servers/ . To use any of them, close the connect dialog window and in the main mIRC window (status window) use /server putthe.serverinfo.here
Any server on any network is subject to splits or downtime, no way to guarantee anything, but as long as you have several servers to use, that isnt a prob. You dont register your nick and channel on a server, its registered on the network.
While you're at DALnet's website, take a look at their help documents area, there is a lot of good info there on a variety of things including managing your channel. Happy chatting
